Reaction of lithium dialkylcuprates with acid chlorides in the presence of oxygen affords carboxylic esters in high yields under mild conditions. Of special synthetic significance is the stoichiometric requirement of only 1 equivalent of alkyl group for ester formation. The preparation of esters from acid chlorides and copper (I) alkoxides has been studied. Reaction of acid chlorides without labile protons with simple copper (I) alkoxides affords the esters in high yields. It has been found that nucleophilic displacement reaction of allyl bromide with copper alkoxide proceeds well. Also, alkylation of ketones with alkyl halides in the presence of copper (I) tert-butoxide has been studied.